1. Filed of the invention
The present invention relates to a color balance adjusting apparatus for use in full-color copiers, and particularly to the color balance adjusting apparatus for use in full-color copiers that operates in link with an automatic control function of image density.
2. Description of the Related Art
In the field of full color copiers, the adjustment of color balance of a color image used to be carried out by using an original having various gradations of gray patches. With such an original, a service engineer would adjust the apparatus such that the gray patches of the original might be reproduced as certain gray colors. In this case, the copying operations used to be repeated while the service engineer adjusting the color balance, or adjusting each toner amount of color components, i.e., yellow, magenta and cyan until the reproduced color of certain patches would be gray.
This series of operations had to be performed for different copy modes.
In the conventional method described above, since the balancing condition of yellow, magenta and cyan is so delicate and unstable that if one component of the colors deviates from the balanced condition to a slight degree, the composed color might be totally off balance. As a result, the service engineers cannot perform a speedy adjustment. Therefore, in the adjustment using the conventional method, the service engineer must practice a lot of testing copies for the adjustment of a machine having multiple modes, so that the number of copies would be increased, and therefore the developer and the photoreceptor would be exhausted or worn out resulting in cost increase. Still, in view of the user side, the adjustment must take a prolonged period of time, so this would cause an unfavorable impression upon users.
As an apparatus for adjusting the color balance automatically, there has been proposed means in which the voltage of lamp is automatically changed to record each toner image of yellow, magenta and cyan on a photoreceptor and the thus created toner images are measured on the density with an infrared sensor. In this case, each colors of yellow, Magenta and cyan must be recorded, therefore the adjustment time, the consumption of power and the use amount of supplies are increased. Besides, in case a user activates the color balance adjustment mode erroneously, the copier remains engaged in operation over a prolonged period of time without discharging any recorded sheet, thus giving the user a feeling of uneasiness.